Hydrostatic pressure release mechanism



Jan. 3, 1961 J. c. GoFF 2,966,851

HYDRosTATIc PRESSURE RELEASE MECHANISM Jan. 3, 1961 J. c. GoFF HYDRosTATIc PRESSURE RELEASE MECHANISM 6 Sheets-Sheet 2 Filed Sept. 29, 1950 L L s ATTYS Jan. 3, 1961 J. c. Gol-'F v.IGHN BY MMM 6 Sheets-Sheet 3 INVENTOR.

C. GFF

ATTYS Javn. 3, 1961 J. c. Gol-F 2,966,851

HYDROSTATIC. PRESSURE RELEASE MECHANISM Filed Sept. 29. 1950 6 Sheets-Sheet 4 IN VEN TOR.

JETOHN C. GOFF BY l //LQ/g @AMA-#JM arrys `V Jan. 3, 1961 J. c. GOFF HYDRosTATIc PRESSURE RELEASE MECHANISM Filed sept. 29. 195o 6 Sheets-Sheet 5 FIG.6.

FIG.5.

INVENTOR. JOHN C. (IOFF Jan. 3, 1961 J. c. Gor-'F Hynaosmwrc PRESSURE: RELEASE MECHANISM Filed sept 29. 195o 6 Sheets-Sheet S FIGJ.

FIG.9.

FIG.8.

WMF/71':

INVENTOR. BillIOHN C. GOP` F JMJ-Lada Arrys.

United States Patent This invention relates generally/.to means fori selectivelyY releasing a slack length of mooringcable from a buoyant marine mine and more specifically to a new and improved depth regulating device smilar to that set forth in the copending application of Joseph D. Turlay for a Depth Regulating Device for a Moored Mine, Serial NumberV 465,931, led November. 17, 1942, now Patent No. 2,706,948, and adapted for releasably maintainingV a bight in a portion of the mooring cable adjacent the mine until the latter has risen within thev water tov a preselected depth of submergence whereuponthe reduc-- tion in the tension upon the mooring cable as the bight is Vreleased causes the cable drum within the mines anchor to lock and thereby in this manner secure the cable, and accordingly the mine attached thereto, within the water at a preselected depth of submersion.

The depth regulating and cable release mechanism of' the present invention is adapted to be empoyed with mines released from a launching craft above thesurface ofthe water or from the torpedo tube of a submarine operating submerged or aoat, as the case'may be, and with the mine and anchor, launched asa unit and sepa rating as they descend through the Water with the interconnecting cable therebetween paying out from a supplyv drum in the anchor as the more buoyant minerises toward mooring position at a selected depth below the surface of the water.

As the mine anchor falls away from the mine during the downward movement thereof within the water, thev pull of the anchor againstthe cable causes the hydrostatic depth' regulating and releasingV device connected thereto yto be withdrawn from a` recessedportion ofthe mines anchor whereupon the pull offthe mine against the mooring cable atvthis time is applied across a pair f detachable pull pins opposingly arranged andy forming a partl of the depth control release mechanism and about which a relatively short length of cable hereinbefore referred to as the bight is connected. Connected to-one end of this bight preferably by a short length of cable is the; mine and to the othery end thereof the upper end of the mooring cable to which is fastened the mines anchor. As the bight is released `by the disengagement of the pull pins from the release mechanism responsive to a preselected setting of the hydrostatic element of the latter, the momentary decreaseV in tens'on in the mooring cable is effective in this manner to produce a locking action upon the cable supply reel disposed within the anchor, now resting upon the bed ofthe body of water, to prevent further payingout of the cable from the reel to accordingly thereby secure the mine at a preselected depth below the surface.y

Whereas, cable release and depth regulatingdevices `of this type heretofore devised are generally designed to respond to hydrostatic pressures between 30 and 90 pounds` in-accordance with selected positions of adjustment made thereon during assembly, changes inl naval tactics nowrequire that such mechanisms operate with ranges of `be tween 30'to 500 pounds and with furtherfprovision there-` in for1 making such pressure responsive adjustments in tl'e ield if necessary, to-conform more accurately to the con# ditions of launching and` location wherein the mines are' to be planted.

In order that these requirementsmay be met, the cable release of the presentinvention. provides an improved; arrangement. for controlling-the pressure response of thel hydrostatic elementv thereof and accomplished by thefprovisiontliereinofa cantilever springarrangement varyf ing in cross section and adjustable selectively in lengthfto? provide a pressure range. heretoforel unobtainable by-- mechanismsof comparablev sizeemploying helical springs?` andzcapableof performing the same mechanical work`.

Itis an object of the present inventiontolprovide a new" andimproved meanszforreleasing a bight in'the-mooringl cable ofa submarine mine when theY mine has'risenvtolw predetermineddepth of submergencev within the water;`

Another'of the objectsA is to provide a new and im` provedcable release device adapted to be armed by a'f predetermined pressure thereon and released-l by a prede# termined pressure of less value than the arming pressure.y`

A stillfurther'object is toprovide anew and improved? cable release mechanism wherein a bightin a mooring; cable of amoored mine is released as the mine risesto a preselected'depth beneath the surface of the water.

An additional object is to provide a new and'improved cable release mechanism wherein thev responsev of.'` the' hydrostatic element thereofV is controlled' by the adjustedi effective spring length of a cantilever beam andthe range!1 of response of the mechanism is greatly'fextended beyond-11 therange ofprior'art devices.

Other objects i and ,manyy oftheattendant advantages Sofri this: inventionV will be, readily appreciatedy as" the same.A becomes better understood by reference-to the'followingA detailed description when considered in4 connection with! theV accompanying drawings wherein: Y

Fig.'` l illustrates in diagrammatic form'the launching and mooring of a submarine mine vemploying the devicel ofthe present invention;

Fig. 2 is a cross sectional view of the cable'releasef device'of the presen't invention in an initial condition;M

Fig. 3 is a plan view of the release device'shown inl Fig. 2 with the cover removed and in release pin .securingVZ position;

Fig. 4 is a plan view of the device of Figs.` 2fand3 withf: the cover removed and the pins released therefrom;

Fig.` 5 illustrates in diagrammatic form the cable release device of the present invention as connected in the moor ing rcabe of the mine;

Fig; 6 illustrates in diagrammatic formthermine moor-r ing cable after the release of thebight therein, thecable? release mechanism having fallen away;

Fig.V 7 is a cross sectional view taken along `lineY 7`7 of Fig. 2;

Fig. 8 is a cross sectional viewvtaken along'line 8-8 of Fig. 2;

Fig. 9 is an end view in elevation of the linkage as-'f viewed along the line 9--9'of Fig. 2;

Fig. l0 is a fragmentary sectionall view'illustrating-'thefplunger of the release mechanismiin. latched position; and*v Fig. 11 is a fragmentary. sectional view illustrating thefY whichis secured as by screws 7' acircular cover plate V8 adapted by means of anO ring gasket 9'interposed therebetween to provide a watertight. closure for theghousi'ng,"v

Arranged somewhat off centerV within thel housing'V 6" and movable axiallyrwithin a vertical` guide bore' 1Q-Tprov vided ythereforJ inl a rectangular formed 'block portion projecting upwardly from the housing base 13. Fig. 2, is a piston 14 adapted to provide an operative connection between a cable release mechanism generally designated 15 and a hydrostat assembly generally designated 16 and including an elongated pressure tank 17 secured as by nuts 18 Vto depending lugs 19 preferably formed integral with the under surface of the housing 6.

z Centrally secured about the lower end of the piston 14 as by a self locking nut and washer 20 and 21 respectively, is a flexible diaphragm member 22 formed preferably from rubber or like material and clamped as by a ring screw 23 about the outer periphery thereof within a threaded opening provided therefor in the upper surface of the pressure tank 17. Asthe diaphragm is thereafter deflected inwardly responsive to a predetermined hydrostatic pressure being applied to the outer surface thereof, the piston 14 centrally secured to the diaphragm is moved thereby downwardly within a guide bore 24 provided therefor in the base section of the tank 17 with the upper end 25 of the piston moving away from the release mechanism 15, arranged within the housing, and thereby to perform an arming operation upon the release mechanism, the significance of which will become more clearly apparent as the description proceeds. An annular plate 27 arranged between the ring screw 23 and diaphragm 22 and clamped with the diaphragm to the tank 17 extends inwardly to within close but spaced adjacency with respect to the piston 14 thereby to provide a protective cover for the diaphragm for the purpose of preventing possible damage occurring thereto during assembly of the device or the subsequent mounting or withdrawal thereof from the casing of a mine during the planting operation.

Inverted over an inclined surface 28 provided therefor upon the upper surface of the tank 17 and secured thereto as by screws 29, Fig. 8, is an elongated U-shaped channel member 30 thereby forming upon the tank an enclosure hereinafter referred to generally as the spring housing 31 and wherein is secured to the end of the tank 17 as by clamping members 33 and 34 respectively, a cantilever spring 35. In order that this spring possess the physical characteristics for producing in the device the wide pressure response required thereof, the spring 35 is preferably tapered in form with a gradually increasing cross section beginning at or near the point ofvsecurement thereof as by screws 36 to the end of the tank 17, Fig. 2, to a thickened end portion 37 projecting outwardly from the end of the housing 31 and wherein is provided in the spring an elongated slot 38 suitable for receiving therethrough the piston 14. A block member 39 interposed between the spring and housing 6 and suitably secured to the piston as by pinning thereto at 41 initially deects the spring 35 to the extent of causing the latter to maintain the block firmly against the under surface of the housing 6, the block 39 further providing for positioning the piston 14 properly with respect to the release mechanism 15 operatively associated with the upper end of the piston, as illustrated in Fig. 2.

Depending from the under surface of the block 39, as viewed in Fig. 2, and adapted for being received within the slot 38 formed therefor in spring 35 is a finger 42 adapted to position the block 39 so that a fulcrum surface 43 thereupon is maintained in the manner indicated, across the spring 35 and whereby the spring is deflected downwardly by this surface as the piston 14 responds to the inward deflection of the diaphargm 22 as will result by the device being submerged the required depth within a body of water.

. Movable longitudinally over the spring 35 as by an ad- Justment screw 49, is a fulcrum assembly generally designated 45 and comprised of a rectangular block member 46 wherein is arranged, as illustrated in Fig. 2, a pair of opposingly spaced rollers 47 adapted for movement within suitably formed tracks 48 preferably milled in the mner surface of the tank and channel memberslj and 30 respectively, Fig. 7 48 are arranged parallel to the respective upper and lower surfaces of the spring 35 the rollers 47 are maintained by the tracks in bearing contact with these respective surfaces during movement thereover of the fulcrum 45 irrespective of the tapered nature of the spring.

Provided on the adjustment screw 49 is a square end section `50 suitable for receiving thereover a wrench or like tool, not shown, whereby the screw may be rotated by the tool for shifting to selected positions of adjustment the fulcrum member 45 along the surface of the spring. An extending flange 52 preferably formed integral with the screw 49, Fig. 2, providing, together with the square end section 50 thereon, a structure suitable for rotatably securing the screw to the tank whereby the fulcrum may be shifted thereby in either direction along the surface of the spring without the separation of the screw from the retaining surfaces provided therefor between the block and tank members 34 and 37 respectively.

As the position of the fulcrum member 45 is shifted along the spring 35 the deliectable length of the latter is altered selectively to conform to that indicated by a pointer 53, Fig. 7, carried by the fulcrum and movable, by way of an elongated slot 55, across a scale 56 secured as by screws 57 to the sidewall section of the channel member 30. The scale is so calibrated as to indicate in feet, or the equivalent thereof, the depth of submergence within a body of water required to deflect the diaphragm 22 of the hydrostat against the opposing force of the adjusted spring 35 whereby the piston 14 is thereby carried by the diaphragm to a second position effective to operate the release mechanism to armed position as will become more clearly apparent as the description proceeds.

Since the deflection of a cantilever beam of uniform cross section under a constant load varies inversely with the cube of the length thereof between the fulcrum and the point of load application, varying the position of the fulcrum will accordingly vary the load required for a constant deflection of the beam in a cube relation whereas, in the present device, adapted for operation in response to a constant deflection of the beam the tapering of the spring 35 increases this relation to a quartic curve or higher thereby to provide a cable release having a far greater range of pressure response than heretofore possible with apparatus previously devised and capable of performing the same mechanical work.

The purpose of the arming operation being performed upon the device and which is accomplished by movement of the piston 14 by the diaphragm of the hydrostat from an initial position to a second position as hereinbefore indicated, assures proper submersion of the mechanism before it can be operated to bight releasing position thereby preventing premature operation of the device before the mine is properly planted. After having been properly submerged the mechanism is operated to bight releasing position responsive to the return of the piston to its initial positionV as will hereinafter be more fully described.

The release mechanism 15 comprises a pair of release or pull pins 60 made annular in form for closely fitting within bores 61 provided therefor in the side wall section of the housing 6 as illustrated in Fig. 3 and with a moisture proof seal being provided about the pins andthe housing as by O-ring gaskets 62 conventionally arranged within grooves provided therefor in the pins and disposed for bearing contact with the inner surface of the bores 61.

Mounted within the housing 6 for rotation about a pair of vertically disposed pins 63 is a pair of locking members 6.4 adapted at 65 for registering engagement with annular grooves 66 provided therefor in the inner ends of the release pins 60'and whereby the pins are secured by these members to the housing concurrently with securing thereto the sections'of the mooring cable 67 and bight 58 Seurd to the ends ofthe pins 69 as by ring members For the reason that thetracks,

:equipped end 87 of the plunger.

epesses 68. Rotation of-the'tlocking 1members- 64 Ainto locking engagement with the release pins 60 is accomplished by movement outwardly from the block. member 11fof a rectangular plunger 69 slideably fitted within Va way or groove 70 provided therefor in the upper surface of the block, Fig. 3, with the lplunger being therein so retained as by a cover plate 71 fastened to the block by screws 72.

The plunger 69 is connected, as illustrated in Fig. 9, with the locking members 64 by way of coordinating links 73 through which pins'74 and 75 extend to be thereafter secured therethrough as by cotter keys 76. A continuous spring 77 arranged about the pins 74-and with the ends thereof overlaying the outer edge of the lower links 73 provides an arrangement whereby an initial biasing force is applied by the spring to the links 73 in a direction forcausing them to rotate about theV pins 74 and toward the plunger 96, Fig. 4, thereby to become effective to release the locking members 64 from their engagement with the release pins 60 upon movement of 4the plunger 69 from the block 11 during the releasing operation of the device as ywill become more apparent as the description proceeds.

The locking members 64 are moved inwardly into locking engagement with the grooves 66 provided therefor in the release pins by movement into the block 11 of the plunger 69 which operates to rotate the locking members about their respective points of pivot and into engagement with the grooves 66 concurrently with cock- .ing the spring 77 as the links 73 are extended outwardly to the position illustrated in Fig. 3.

Vertically disposed to the side of the block member 11 and rotatably mounted within a drilled stud provided therefor, but not shown, in the base of the housing 6 and within a cylindrically formed guide 80 extending upwardly from the outer surface of the cover plate `1s an arming shaft 81 having formed integrally therewith an extension hereinafter referred to as the safety arm 82. A second arm 83 hingedly secured as at 84 adjacent the lower end section of the shaft 81 is arranged for horizontal movement within a slotway 35 provided therefor in the block 11 as illustrated to advantage in Fig. 2.

The plunger 69, upon movement inwardly into the guide surface 70, is secured in this inward position by downward movement thereover, and thro-ugh which the shaft extends, of a locking lug 86 adapted to be seized by a latch equipped end 87 of the plunger as the locking member 64 are rotated thereby into engagement with lthe annular grooves 66 in the release pins 6i). The locking lug S6 when in this locking position over the latch 87 rests substantially upon the end of the pisto-n 14, Fig. 2, and initially with the safety arm 82, so disposed above an extending flange section 88 on the lug that lifting of the lug from the latch is thereby prevented until such time as the arm is rotated from the flange to lug releasing position, Fig. 4, `as accomplished by vthe withdrawal of the arming pin 93 from the arming shaft 81.

The initial position of the safety arm 81 above the flange 88 places the lower arm S3 outwardly within the groove 85, as illustrated in Fig. 2, with a biasing force being applied to the arm in the direction for causing movement thereof toward the piston 14 by the connection therewith of a spring 89 extended between the end of the arm 83 and a lug 90, Fig. 3, projecting upwardly from the base of the housing 6.

The operation of the cocking or arming the mechanism following the assembly thereof is accomplished by the insertion of a bar or like tool within an opening now shown closed as by a cap screw 79 and thereby to apply sufficient force to the extended end of thel plunger 69 as to urge it inwardly into the block 11 to the position for allowing the locking lug 86 to descend over the latch The lug 86 is 'urged downwardly over the latch by the karrangement over the lug vof'a helical spring member 91 .interposedbetween .the upper-,endA of the lug and. the.. cover plate 8 wherein .thespring .is retained.

The locking of the lug $6 in plungensecuring position, as indicated in Fig. 2, is accomplished by a wrench or like tool being-applied toothezsquare endsection92, Fig. 3, of the arming shaft 81 to Yrotate the shafttothe position for moving the arm V52 above Vthe flange S8 Vof lug concurrently with the alignment of horizontally drilled openings provided .therefor in the guide andv shaft members -andi81 respectively whereby theremay fbe inserted therewithin an arming pinr93.for.maintaining the shaft 81 against further rotation untilthepin is subsequently extracted therefrom during lthe launching Voperation of :the mine. A

The release device, to which are securedrthe-end's of the mooring cables 67 and bight 58, is arranged within .a recess provided therefor, but not shown, betweenfthe mine l94 and anchor`96 andradaptedrfor'fbeing withdrawn fro-m this recess as the anchor fallsv away` from vthe mine during the downward descentiof .the mine and anchor within the water following the. launching of the mine as hereinbefore described. The release device 5 byrbeing secured iniclose adjacency to the mine, Fig. 5, an arming wire 95Y secured to the arming pin 93 and in a manner not shown to the anchor 96, operates'to withdraws-the pin Vfrom the. mechanism as the morebuoyant Vmine moves a preselected distance from the anchor, Fig. 1,

during its ascent toward the surface `Vofthe water.

The releasing of the shaft Y31 -by the withdrawal of the arming pin 93 therefrom causesthe rotation of the arm 83, as drawnvby the spring 89, `to a position against the side of the piston shaft 14,V FrigVl'O, whereupon-as vthe pressure againsttheouter surface of the-diaphragm 22 becomes sufficient to overcome .the forceexerted upon the piston` by the spring 35 ythepisto-n is carried-downwardly by the diaphragm from its position againstrthe under-surface. of the. lug .86 sutlicientlyvfor allowing .the

spring `89 todrawthe arm beneath lthe lug to-the position indicated in Fig. 11. This operation completes the arming ofthe mechanism effective, asy hereinbefore described, to insure propervsubmergence of the mine within a body of water before the-device can `thereafter be` operated to bight release position7 As the mine 94 rises within the water followingthe arming thereof the resultant llessening in the hydrostatic pressure against the diaphragm22 to a value sufficient l:to allow the spring 35 -to lift the piston 14 whereby theend of Vthe piston is thereby `brought to bear against the 'under `surface of the arm yS3causing a lif ing of the arm andaccordingly the block 86 from latching engagement with Ythe plunger 64, Fig. 1l. When this occurs, the piston-has completed a cycle of operations and the plunger snaps to refractive position, Fig. 4, by the urge of spring 77 causing the rotation of the latching .members 64 from engagement with the pins 60 whereupon Vthe pinsf-are-drawnby vthe mooring cable 67 free Yof the housing-6 allowing the mechanism 5 to fallffrom the cable, Fig. 1. The release of the bight or slack loop 58 produces a momentaryi-nterruption in tension inthe mooring cable required tocause locking of the cable supply reel, .not shown, disposed within the anchor and now .resting upon the bed ofthe body of water.

-Obviously many modifications Vand variations Vof the present invention are possible inthe `light of therabove teachings. kIt is'therefore` to be understoodthat within the scope of the appended claims the invention-.maybe practiced otherwise than as specifically described.

The invention described herein may bemanufactured and used by or for the Government ofthe `.United States of America for ,governmental purposes without .thepayment of any royalty thereon or therefor.

What is.claimed asnew and desired to besecured by Letters Patent of the United States is:

1 A device for releasing a bight inthe mooring-cable of .a 'submarine mine-including, `.in combination, .vashydrostat, a bight release mechanism, a piston movable by said hydrostat, means in engagement with and movable by said piston sufficiently to operate said release mechanism to bight releasing position as the piston is moved a predetermined amount by hydrostat pressure applied to the hydrostat, a cantilever spring arranged for opposing movement of said piston by said hydrostat, and settable means movable along the surface of said spring to change the effective length of the spring thereby to selectively vary the opposition of said spring to said movement of said piston.

2. A device for releasing a bight in a mine cable including, in combination, a hydrostat, a piston movable by said hydrostat, a release mechanism operatively connected to said piston and repsonsive to a predetermined movement thereof to etect the release of said bight, a cantilever spring disposed for resisting the movement of said piston by said hydrostat, and means movable over the surface of said cantilever spring for selectively varying the eiTective spring length thereof thereby to control the depth at which the hydrostat is effective to cause release of said bight.

3. A device for releasing a bight in a mine mooring cable including, in combination, a movable piston, a bight release mechanism including a movable element in engagement with said piston and responsive to a predetermined degree of movement thereof to eifect the release of said bight, means including a hydrostat for applying said movement to the piston, a cantilever spring disposed for yieldably opposing movement of said piston by said hydrostat, an adjustable fulcrum moveable to different settings along the surface of said spring respectively corresponding to diierent depths at which the bight is to be released thereby to alter selectively the opposition of said spring to movement of said piston.

4. An underwater device for releasing a bight in the mooring cable of a submarine mine including, in combination, a piston, a hydrostat responsive to the pressure of the surrounding water to effect movement of said piston, a release mechanism operatively connected to said piston and responsive to a preselected cyclical movement thereof to effect the release of said bight, a cantilever spring secured at one end and disposed for dellection by movement of said piston, a fulcrum movable adjustably over said spring to vary selectively the portion thereof deectable by said piston, and means forming a part of said fulcrum for opposing reverse deilection of said spring between said fulcrum and said secured end thereof.

5. A device of the character disclosed for releasing a bight in a mine mooring cable including, in combination, a housing, a pair of release pins operatively connecting said cable at the ends of said bight, releasable means including a latch for releasably securing said pins to said housing and responsive to a release of said latch to release said bight, a hydrostat, a piston movable by said hydrostat from an initial position to an armed position responsive to a predetermined increase in hydrostatic pressure applied to said hydrostat, a tapered cantilever spring fixedly secured at the smaller end thereof and disposed for deilection at the other end by movement of said piston as the piston is moved to said armed position, a pair of tracks carried by said hydrostat and arranged on opposite sides of said cantilever spring and parallel to the upper and lower surfaces thereof respectively, an adjustment screw, a fulcrum member arranged for bearing contact upon the said surfaces of said spring and movable thereover by adjustment of said screw to alter selectively the deectable length of said spring, and means responsive to movement of said piston to said armed position to release said latch upon the return of said piston to said initial position by said spring in response to a reduc- `tion in hydrostatic pressure applied to the hydrostat.

6. An underwater device of the character disclosed for releasing a bight in a mooring cable for a suboating inine including, in combination, a housing, a pair of release pins connected respectively at the ends of a length of said cable, means including a latch for releasably securing said pins to` said housing thereby to form a bight in said cable, Va block carried by said housing and movable for engaging said latch for maintaining said securing means in pin securing position, biasing means for effecting movement of said securing means to pin releasing position upon disengagement of said block from said latch, a piston, a hydrostat responsive to a predetermined hydrostatic pressure of the surrounding water to effect movement of said piston from a rst -position to a second position, a cantilever spring disposed for yieldably opposing movement of said piston by said hydrostat and to return said piston to said iirst position upon a predetermined decrease in said hydrostatic pressure upon the hydrostat, and means responsive to movement of said piston to said second position to effect the disengagement of said block from said latch upon return of said piston to said first position thereby to release said bight of cable.

7. A device of the character disclosed for releasing a bight in a mine mooring cable including, in combination, a housing, a pair of release pins operatively connecting in said cable the ends of said bight, releasable means including a latch for releasably securing said pins to said housing in response to the release of said latch to release said bight, a hydrostat, a piston movable by said hydrostat from an initial position to an armed position in response to a predetermined increase in hydrostatic pressure applied to said hydrostat, a cantilever spring disposed for opposing movement of said piston by said hydrostat, a fulcrum member movable adjustably over said spring to selectively control the opposition thereby of said piston movement, and means responsive to movement of said piston to said armed position to release said latch upon the return of said piston to said initial position.

8. A device of the character disclosed for releasing a bight in a mine mooring cable including, in combina.- tion, a housing, a pair of release pins operatively connecting in said cable the ends of said bight, releasable means including a latch for releasably securing said pins to said housing and responsive to the release of said latch to release said bight, a diaphragm, a second housing enclosing one side of said diaphragm, a piston movable by said diaphragm from an initial position to an armed position in response to a predetermined hydrostatic pressure applied to the unclosed side of said diaphragm, a centilever spring disposed for opposing movement of said piston by said diaphragm and movable to return said piston to said initial position upon a predetermined decrease in said hydrostatic pressure, and means responsive to movement of said piston to said armed position to release said latch upon the return of said piston toward said initial position.

9. A device of the character disclosed for releasing a bight in a mine mooring cable including, in combination, a housing, a pair of release members operatively connecting in said cable the ends of said bight, releasabie means including a latch for releasably securing said members to said housing and responsive to a release of said latch to connect in said cable said bight, a piston, a hydrostat responsive to a predetermined hydrostatic pressure for moving said piston from an initial position to an armed position, a cantilever spring disposed for moving said piston from said armed position to said initial position upon a predetermined reduction in said hydrostatic pressure applied to said hydrostat, and means responsive to movement of said piston from said initial position to the armed position to release said latch as the piston is returned to said initial position by said spring in response to a reduction in said hydrostatc pressure applied to the hydrostat.

10. An underwater device of the character disclosed for releasing a bight in the mooring cable of a suboating mine including, in combination, a housing, a pair of release pins removably arranged within said housing and connected respectively to said cable and the ends of said bight, securing means including a latch for releasably securing said pins to said housing, a block movable for engaging said latch for maintaining said securing means in said pin securing position, biasing means for eiecting movement of said securing means to pin releasing position upon disengagement of said block from said latch, a piston, a hydrostat responsive to a predetermined hydrostatic pressure of the surrounding water to effect movement of said piston from a rst position to a second position, a cantilever spring disposed for deilection by movement of said piston from said first position, a pair of tracks arranged on opposite sides of said spring parallel to the under and upper surfaces thereof respectively, -an adjustment screw, a fulcrum arranged for bearing contact with the said surfaces of said springs and movable thereover by adjustment of said screw thereby to alter selectively the deflectable length of said spring, and means responsive to movement of said piston to said second position to eect the disengagement of said block from said latch upon return of said piston to said rst position by said spring in response to a reduction in the .hydrotatic pressure applied to the hydrostat.

11. An underwater device of the character disclosed for releasing a bight in a mooring cable for a suboating mine including, in combination, a housing, a pair of release pins removably arranged within said housing and connected respectively to said cable and to the ends of said bight, means including a latch for releasably securing said pins to said housing, a `block movable for engaging said latch for maintaining said securing means in said pin securing position, biasing means for effecting movement of said securing means to pin releasing position upon disengagement of said block from said latch, a piston, a hydrostat responsive to a predetermined hydrostatic pressure of the surrounding water to effect movement of said piston from -a rst position to an armed position, a cantilever spring disposed for deection by movement of said piston from said rst position, `a pair of tracks arranged on opposite sides of said spring and parallel to the respective upper and lower surfaces thereof, an adjustment screw, a fulcrum member movable by said screw along the surface of said spring, a multiplicity of rollers carried by said fulcrum member and disposed for bearing contact respectively with the surfaces of said spring and movable in said tracks by adjustment of said fulcrum member by said screw, and means responsive to movement of said piston to said armed position to effect the disengagement of said block from said latch upon the return of said piston to said rst position.

References Cited in the le of this patent UNITED STATES PATENTS 

